1. Field of the Invention
The subject invention relates to a burn-in socket for a gull wing semiconductor package.
2. Description of the Prior Art
Semiconductor packages are arranged with several lead configurations denoting their use. One such semiconductor package is known as the gull wing package and includes a plurality of leads extending from the package body from all four side edges of the package body and all leads extending outwardly from a common flat plane. The leads are then bent downwardly and then flattened to form a foot which are in a plane which is beneath the bottom surface of the package body.
Typically, all semiconductor packages are tested in some manner to ensure their proper functioning, including burn-in testing where the devices are inserted into sockets and installed within large convection ovens and the packages are operated at elevated temperatures.
The package known as the gull wing semiconductor is a very fragile component and, as such, the package is typically installed within a carrier which includes an insulative housing to surround the package body. The carrier is placed within the socket during the burn-in testing and, when completed, the carrier and package are removed and the semiconductor package is shipped within the carrier for protection of the package leads.
Semiconductor packages are now being manufactured in the four sided gull wing configuration with the lateral centerline between adjacent leads spaced apart 0.025 inches with as many as 244 leads extending from the package body. With an insertion force on each lead being approximately 0.25 pounds, the total insertion force for such a semiconductor package would be as high as 61 pounds total. The problem which resultantly exists is the necessity of an insertion and latching means which can progressively install the package leads yet maintain and retain the semiconductor package in an electrically connected condition with the terminals of the burn-in socket.
Burn-in sockets presently available require the semiconductor package and the carrier to be inserted within the sockets and require the installer to exert a force directed onto the package carrier to a position where the package carrier clears a latching mechanism. Two problems are presented by this arrangement.
First, burn-in cycling requires a massive "burn-in board" which is a printed circuit board having densely packed burn-in sockets aligned side-by-side and end-to-end on the board. To require the installer to insert this small semiconductor and carrier within the sockets requires a great deal of dexterity, as the carriers are in the range of one and one inches square, and also requires a lot of physical strength given that the force of 60 pounds must be concentrated on that small of a carrier.
Secondly, the contacts within the sockets can easily be damaged by the installer. If the carrier is over extended within the socket housing, the contacts can be overstressed to the point of plastic deformation.
No such sockets are known to be available which assist in the insertion of the carrier to effect the electrical connection between the semiconductor package leads and the electrical terminals of the burn-in socket.